Pseudo-class selectors describe the state of an element, such as :hover or :empty. On a style sheet, they are preceded by a single colon.

As their name suggests pseudo-element selectors control the presentation of a portion of content, such as the first line or letter of a paragraph. Formally, they are preceded by a double colon (::), although a single colon will work in most cases.

This list is not yet exhaustive: pseudo-class selectors such as ::hover are used extensively in tutorials on this site, but do not yet have their own individual articles. As soon as that changes, they will be added here.